Table 2 Various SMS formulation request scenarios and their respective expected responses

Non-registered user

The number [phone number] does not belong to an active user who is authorised to randomise study participants at [site name]. Contact [ administrator contact] for more details

Exhausted allocation list

Random allocations to the [study name] study is no longer available. Please contact the study co-ordination centre [Phone number]

Invalid message format

Incorrect message format; use: randomise [IPNO] to [studyID] [siteID] or: randomise [IPNO] to [studyID] [siteID] [phoneNO] without the straight brackets. You may also add your phone number at the end of the message if using an authorised phone that does not belong to you

An attempt to randomise a participant twice

The participant with the [IPNO] is already allocated [allocation] by [username] at [timestamp]

An attempt to deactivate non-existing user

Deactivation failed; there is no record with the phone number [phone number] in the list of users

Successful user deactivation

The user with the phone number [phone number], is now an inactive user

Successful user registration

[Username] phone number [phone number], has been added to the list of users authorised to randomise participants to the [study name] study at the [site name] site

Delete user

The phone number [phone number], has been removed from the list of users

An attempt to add user twice

[username], phone number [phone number], already exists in the list of users

Successful randomisation

Participant [IPNO] has been randomised to [allocation] in the [study name] study. The unique number for the participant is [participant randomisation ID]. Randomised by [trial staff name] on [timestamp]